swarmbucket: add get_builders api

appengine/cr-buildbucket/api.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import functools
 import json
 import logging
 
 from google.appengine.ext import ndb
+from protorpc import messages
+from protorpc import message_types
+from protorpc import remote
 
 from components import auth
 from components import utils
-from protorpc import messages
-from protorpc import message_types
-from protorpc import remote
 import gae_ts_mon
 
 import acl
 import config
 import endpoints
 import errors
 import model
 import service
 
 
@@ skipping 143 matching lines @@
       logging.warning(
         'Authorization error.\n%s\nPeer: %s\nIP: %s',
         ex.message, auth.get_peer_identity().to_bytes(),
         svc.request_state.remote_address)
       raise endpoints.ForbiddenException(ex.message)
   return decorated
 
 
 def buildbucket_api_method(
     request_message_class, response_message_class, **kwargs):
-  """Extends auth.endpoints_method by converting service errors."""
+  """Defines a buildbucket API method."""
 
   endpoints_decorator = auth.endpoints_method(
     request_message_class, response_message_class, **kwargs)
 
   def decorator(fn):
     fn = catch_errors(fn, response_message_class)
     fn = endpoints_decorator(fn)
     fn = ndb.toplevel(fn)
     def ts_mon_time():
       return utils.datetime_to_timestamp(utils.utcnow()) / 1000000.0
@@ skipping 455 matching lines @@
     bucket = config.Bucket.get_by_id(request.bucket)
     if not bucket:
       raise endpoints.NotFoundException('bucket %s not found' % request.bucket)
     return BucketMessage(
       name=request.bucket,
       project_id=bucket.project_id,
       config_file_content=bucket.config_content,
       config_file_rev=bucket.revision,
       config_file_url=config.get_buildbucket_cfg_url(bucket.project_id),
     )